Many people have trouble distinguishing between possessive nouns and plural nouns. Possessive nouns and pronouns demonstrate ownership or some similar relationship over something else. Plural nouns indicate more than one person, place or thing.

Look for the Apostrophe

Possessive nouns typically include an apostrophe. For example:

Jennifer’s imagination ran wild as she pictured the accident.

The kitten’s toy is a stuffed catnip mouse.

Think of the apostrophe mark as a hook or hand reaching out to take ownership of the object. Without the little hook or hand grabbing onto the ‘s’ or the next word, the noun is simply plural.

Possessive Nouns as Personal Pronouns

Some possessive nouns are actually personal pronouns. A pronoun is a word that can stand in for the noun in a sentence. Pronouns are often used to keep sentences from sounding rambling or redundant. Personal pronouns reflect ownership when used appropriately in a sentence, and do not get the apostrophe + s added to them.

Grammar Rules for Possessive Nouns

Rule #1: Making singular nouns possessive

Add an apostrophe + s to most singular nouns and to plural nouns that do not end in s.

You’ll use this rule the most, so pay particular attention to it. English has some words that are plural but do not add an ‘s’. Words like children, sheep, women and men are such words. These plural words are treated as if they were singular words when making noun possessives.

Rule #2: Making plural nouns possessive

You don’t need to add an extra ‘s’ to plural nouns that already end with the letter ‘s’. Simply tuck the apostrophe onto the end to indicate that the plural noun is now a plural possessive noun.

Examples:

Companies’ workers

Horses’ stalls

Countries’ armies

Rule #3: Making hyphenated nouns and compound nouns plural

Compound and hyphenated words can be tricky. Add the apostrophe + s to the end of the compound words or the last word in a hyphenated noun.

Examples:

My mother-in-law’s recipe for meatloaf is my husband’s favorite.

The United States Post Office’s stamps are available in rolls or in packets.

Rule #4: Indicating possession when two nouns are joined together

You may be writing about two people or two places or things that share possession of an object. If two nouns share ownership, indicate possession only once, and on the second noun. Add the apostrophe + s to the second noun only.

Examples:

Jack and Jill’s pail of water features prominently in the nursery rhyme.

Abbot and Costello’s comedy skit “Who’s On First” is a classic act.

Rule #5: Indicating possession when two nouns are joined, and ownership is separate

This is the trickiest of all, but thankfully you’ll probably need this rule infrequently. When two nouns indicate ownership, but the ownership is separate, each noun gets the apostrophe + s. The examples below may help you understand exactly what this means.

Example:

Lucy’s and Ricky’s dressing rooms were painted pink and blue. (Each owns his or her own dressing room, and they are different rooms).

Senator Obama’s and Senator Clinton’s educations are outstanding. (Each senator owns his or her education, but they attained separate educations).

Personal Pronouns

Personal pronouns never use the apostrophe to show ownership. Personal pronouns are words like my, your, her, his, our, their and its. They already imply ownership within the word itself.

Examples:

Your cell phone is ringing. (Personal pronoun possessive)

Rob’s cell phone is ringing. (Singular noun possessive)

It and It’s

One of the biggest sources of confusion to writers is the difference between its and it’s. Normally the noun possessive is formed by adding apostrophe + s. However, we just mentioned that personal pronouns never take the apostrophe + s. It is a personal pronoun used to describe things. “It’s” is a contraction between the words “it is.” Contractions are two words shortened into one.

A good rule of thumb to check your own writing is to try to substitute the words “it is” every time you use “it’s." If the sentence makes sense, you’ve used it correctly. If the sentence does not make sense, reach for the possessive case and use instead “its.”

Lesson Plans, Worksheets and More on Possessive Nouns

Lesson Tutor is a free website offering information and activities on dozens of English grammar topics, including possessive nouns.

A group called Funding Factory offers detailed lesson plans on possessive nouns.

A great resource site for ESL teachers is ESL Printables which includes reproducible worksheets for classroom use.

Elementary through college instructors turn to Mad Libs lesson plans for fun, interactive ways to learn English grammar.

Bottomline: Possessive nouns and pronouns demonstrate ownership or some similar relationship over something else.